(1) The reactivity of functional groups attached to cross-linked polymer beads will be studied as a function of the network structure, to provide background information for the "solid-state synthesis" of polypeptides and proteins. (2) The attack of enzymes on side chains of synthetic polymers will be studied to provide background information for a possible method of sustained drug release. (3) The interaction of reactive groups attached to two polyanions will be studied to aid the interpretation of data on DNA renaturation. (4) The adsorption of flexible macromolecules onto monodisperse latex particles will be studied in connection with the use of such latex as a tool in medical diagnosis.